The present invention is directed to Thermoplastic Compositions Resin Molded Products which are useful for vehicle linings such as door trim, shelf covering and package trays and to a method for manufacturing thermoplastic resin molded products which are useful in the vehicle lining field. And more particularly, the thermoplastic resin molded products disclosed herein are in the form of a thin plate, which is formed from a homogeneous admixture of thermoplastic resin, fillers, and additives.
There have been a number of approaches for manufacturing vehicle lining materials and similar products such as wood substitutes, plastic products and the like. For example, the Korean Patent Publication No. 234/1975 (Published July 9, 1975; for a Method for Manufacturing Substitute Wood Products) discloses compositions which comprise mainly briquette ash and waste rubber as the primary raw materials.
This composition functioned as a substitute wood product, but was relatively heavy, was difficult to mold and had poor heat resistance and workability, and high cost.
A second approach is disclosed in Korean Patent Publication No. 1091/1979 (Published Aug. 26, 1979, Moldable Synthetic Resin Composition) . This reference discloses a composition of novolak type phenol resin and silicic acid hydrate Aluminium (Al.sub.2 O.sub.3.2Sio.sub.2.2H.sub.2 O) as fillers. The composition has excellent release properties but poor workability and moldability.
A further approach is disclosed in Korean Patent Publication No. 88/1979 (Published Mar. 12, 1979); for A Method For Manufacturing Nonflammable Substitute Plastic Products. This reference discloses a method which comprises adding additives such as briquette ash, diatomaceous earth, pitch, waste rubber etc and fire retardants. The product has good fire retardant properties, but is relatively heavy and may be harmful to the environment.
The Japanese Patent Publication No. 42008/1977 (Published Sept. 16, 1983) discloses a method for coloring a wood flour filled thermoplastic resin. However, the method disclosed therein uses the wood flour only as a means for coloring the product. Further, the product has relatively poor heat resistance, water absorption and shrinkage.
The Japanese Patent Publication No. 41324/1982 (Published Sept. 2, 1982) for; A Method For Extruding Filler-Containing Thermoplastic Resin discloses a method for extruding admixtures of thermoplastic resin and inorganic fillers. The fillers include talc, calcium carbonate, and kaolin. Therefore, the products have relatively weak tensile strength and flexural strength and are also relatively heavy in weight.
The Japanese Patent Publication No. 38368/1981 (Published Sept. 5, 1981); discloses A Method For Manufacturing Particle Crystalline Polyolefin for use in molding. This publication discloses a method which incorporates inorganic fillers such as talc, kaolin, magnesium carbonate, calcium, carbonate, barium sulphate; titanium oxide and zinc oxide. The products using the above fillers have relatively poor tensile strength and flexural strength. Further, the products are relatively heavy.
The U.S. Pat. No. 3,976,608 (issued Aug. 24, 1976); discloses a process which incorporates fillers such as calcium carbonate, talc, asbestos fibres, glass fibres, wood sawdust, wood flour and mica and polystyrene; and a moldable filled polystyrene product. However, these products which include the listed fillers are less satisfactory as fire retardants, and have less dimensional stability and tensile strength than the improved products disclosed herein.